<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Python编程</title>
  <style>
    .continer {
      margin: 0 auto;
      width: 80%;
    }
    .box {
      margin: 0 auto;
      width: 100%;
      text-align: center;
    }
  </style>
  <script type="text/javascript">
    function clear_code(id){
        if (document.getElementById(id).value == "代码拷到这里！") {
            document.getElementById(id).value = "";
        }
    }
</script>
</head>
<body>
  <div class="continer">
    <div class="box">
      <h1>课后作业提交</h1>
      <form action="/" method="post" accept-charset="utf-8">
        <div><span>学号：</span>
          <input type="text" name="usertag" style="width: 20%;"/>
          <span style="width: 5%; display:inline-block"></span>
          <span>密码：</span>
          <input type="password" name="password" style="width: 20%;"/>
        </div><br>
        <div>
          <textarea name="code" id="codebox" rows="10" wrap="off"
            style="width:100%;overflow-y:scroll;overflow:scroll;"
            onclick="clear_code(this.id)">代码拷到这里！</textarea>
        </div><br>
        <div style="margin: 0 auto; text-align: center;">
          <input type="submit" value="提交代码" 
             style="width:100px; line-height:99px;display:inline-block"/>
        </div>
      </form>
    </div>
    <div><span id="info"/></div>
  </div>
</body>
</html>